fatigued with headaches and severe nausea

Female * 29 years * HISTORY: Endometriosis, left nephrectomy 2013, 100mg daily of Zoloft for anxiety.
Hi, I have been extremely fatigued with headaches and severe nausea coming in waves (no pattern to it, but I do have it almost every night). I have no real appetite, but am eating, although not a great diet. I also have shoulder tip pain in my left shoulder and left side flank pain (kidney has been checked with bloods and an ultrasound-all okay) This has been occurring since August, when I was hospitalised for severe hydration and what doctors diagnosed as possible food poisoning. I was extremely unwell for three weeks with nausea, vomiting and diarrhoea. Also, my period is usually around the 20th of each month and lasts for 4-5 days. This month it arrived on the 12th and lasts for 9-10 days and was extremely heavy. So heavy I could not even wear a tampon. Just after advice from another source.
Thank you.